Reinforced steel column.



PATENTED NOV. 12, 1907.

E. SWBNSSON.

REINFORCED STEEL COLUMN.

APPLICATION PIH'BD JUNE 17. 1907.

W/f/KiSS/SIS UNITED STATES PATENT oEEioE.

ERIC SWENSSON, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR TO MINNEAPOLIS STEEL& MACHINERY COMPANY, OF MINNEAPOLIS, MINNESOTA, A CORPORATION.

REINFORCED STEEL COLUMN.

Specification of Letters Patent.

Patented Nov. 12, 1907.

Application filed June 17. 1907- Serial No. 379.863.

To all whom it may concern:

I Be it known that I, ERIC SwnNssoN, a citizen of the United States,residing at Minneapolis, Hennepin county, Minnesota, have inventedcertain Improvements in Reinforced Steel Columns, 01' which thefollowing is a specification.

The object of this invention is to provide a steel column, reinforced byconcrete, which two materials in combination make a column strong enoughto carry the entire dead and live loads upon said column, which is to bean integral part of any structure suitable for this kind ofconstruction. Said combination of the two materials, the steel and theconcrete, are intended to provide a maximum of strength together with aminimum of material,,with certainty, ease, and facility of erection, andalso intended to constitute an improved fire proof construction.

To this end the invention consists in the constructions and combinationshereinafter described and particularly pointed out in the claims.

In the accompanying drawings for oing part of this specification, Figure1 is an elevation partly broken away, of a column embodying myinvention. Fig. 2 is ahoriz ontal transverse section of the same. Fig. 3is an elevation showing a modified column. Fig 4 is a horizontaltransverse section of the column shown in Fig 3. Figs. 5 and 6 aredetail views illustrating the means for rigidly securing thelongitudinal rods to the I-section.

In carrying out this invention, I provide an I-section formedprel'erably of two pairs of oppositely arranged angle-irons 1 and 2laced together by the diagonal bars 3. A single system of these barsmaybe employed, or, if preferred, a double system of such bars may bearranged to lacethe angle-irons together. In any case, this web lacingis to be snflicient to provide for any web stresses in the columnengendered by dead load during construction or erection, and also inconjunction with the wiring and concrete further on men tioned, .toprovide for possible web stresses when the column is in full actionunder totaldead and live load.

For columns carrying heavy loads I may insert a system of longitudinalrods 4 extending the whole length of the column as shown in Figs. 1 and2, but for ordinary construction a column without these rods is usuallysufiicient. If these longitudinal rods are used, they-,will preferablybe rigidly fastened to the I-section.

Any suitable means may be einployed for securing the rods to the lsection, but I prefer to employ brackets l l l 4 bolted to the I-sectionand having clips 4 for clasping the rods and holding them in place onthe brackets.

Outside the Isection and longitudinal rods 4 and at a small distancefrom the face of the concrete, as shown in Figs. 2 and 4, I provide astrong steel wiring 5. This wiring is to be circular in shape, wound thewhole length of the column with a suitable pitch and is to be held toits proper pitch and place by the longitudinal spacing bars, rods orwires 6. "he purpose of this wiring is to increase the compressiveresistance of the con crete and to prevent the concrete fromdisintegrating or flaking off the steel during stress. My experimentshave shown that, if this wiring is rightly proportioned, as to size andpitch, the concrete will adhere to the steel and take its proper shareof the stresses engenderedby the loads under which the column is acting,even when these loads will rupture the steel framing. This the concreteotherwise will not do. But,'in addition to thus greatly increasing thestrength of the column, this wiring also greatly increases the fireprool' qualities of the construction, because even under most severelire the concrete will crack off only until the wiring is reached and nofurther, thus leaving the strength of the column nearly unimpaired.lu-l'act, this wired concrete will have the same lire resistancerelative to plain concrete as wire glass has to plain glass.

Thus it is to be clearly understood that this rciuforced steelconstruction of columns here shown and described has for its object notonly the use of concrcl c as a necessary fire proofing, but also its useas a large and important factor contributing to the carrying capacity ofthe column, the wiring greatly augmenting the compressive strength ofthe concrete; said wiring also making the concrete act conjointly andharmoni ously with the steel framing, thus enabling me to obtain thesame simultaneous factor of safety in both materials. all which fullsize tests made by me has shown to be true.

I do not limit myself to the details of the construction as these may bevaried in many particulars without departing from my invention, theaccompanying drawing and the above description being lnlcuded to showonly fundamental essentials.

I claim as my invention:

1 A reinforced steel column, comprising, in couibina tion, an l-sectionformed of oppositely arranged angle-irons laced together, a steel wiringsurrounding said Lsection, and a concrete filling, substantially asdescribed.

2. A reinforced steel column comprising, in combination, an I-sectionformed of oppositely arranged angle-irons laced together, a steel wiringsurrounding said I-section, said steel wiring being held to its properplace and pitch by longitudinal spacing bars, rods, or wires, anda-concrete filling, substantially as described.

3. A reinforced steel column comprising, in combination, an I-sectionformed of two pairs of oppositely arranged angie-irons, diagonal lacingstraps connecting said pairs of angle-irons, a system of longitudinalrods on both sides of the I-sectlon, extending the entire length of thecolumn and being rigidly fastened to the I-section, a steel 10 wiringsurrounding said I-section and said rods and a concrete filling,substantially as described. I

In witness whereof, I have hereunto set m'yhand this 7th day of June1907.

ERIC SWENSSON.

- Witnesses: v

- J. B. ERA,

J. H. BALnwIn

